if( clientChallenge == null ) {
clientChallenge = new byte[8];
RANDOM.nextBytes( clientChallenge );
}
HMACT64 hmac = new HMACT64(md4.digest());
hmac.update(username.toUpperCase().getBytes(
"UnicodeLittleUnmarked"));
hmac.update(domain.toUpperCase().getBytes(
"UnicodeLittleUnmarked"));
byte[] ntlmv2Hash = hmac.digest();